[stdlib] Begin exposing the NSString API directly on String

Because we're using a "brute-force" combination of conversion to
NSString and forwarding, this code will continue to work when String
is replaced by NewString.  It may not be fast yet, but at least it
will flesh out the experience for Cocoa programmers

Swift SVN r11034

test/stdlib/NSStringAPI.swift

@@ -0,0 +1,41 @@
+// RUN: rm -rf %t/clang-module-cache
+// RUN: %swift -i -module-cache-path=%t/clang-module-cache -sdk=%sdk %s | FileCheck %s
+// REQUIRES: sdk
+// REQUIRES: swift_interpreter
+
+import Foundation
+
+func testClassMethods() {
+  var encodings: NSStringEncoding[] = String.availableStringEncodings()
+  // CHECK: available encodings found
+  // CHECK-NOT: 0 available encodings
+  println("\(encodings.count) available encodings found")
+
+  // CHECK-NEXT: defaultCStringEncoding is available
+  var defaultCStringEncoding = String.defaultCStringEncoding()
+  for e in encodings {
+    if e == defaultCStringEncoding {
+      println("defaultCStringEncoding is available")
+    }
+  }
+
+  // CHECK-NEXT: It is called
+  println("It is called \"\(String.localizedNameOfStringEncoding(defaultCStringEncoding))\"")
+
+  var path = String.pathWithComponents(["flugelhorn", "baritone", "bass"])
+  // CHECK-NEXT: <flugelhorn/baritone/bass>
+  println("<\(path)>")
+
+  // CHECK-NEXT: true
+  println(String.string() == "")
+
+  // CHECK-NEXT: <sox>
+  var chars: unichar[] = [ unichar('s'.value), unichar('o'.value), unichar('x'.value) ]
+  var sox: String = String.stringWithCharacters(chars.base, chars.count)
+  println("<\(sox)>")
+}
+
+
+testClassMethods()
+// CHECK: done!
+println("done!")